Sleeve clutch



United States Patent [72] Inventors DonaldJ.Fergle St. Clair Shores;Dale K. Benedict, Royal Oak, Mich. [21] Appl. No. 763,784 [22] FiledSept. 30, 1968 [45] Patented Dec. 15, 1970 [73] Assignee Eaton Yale &Town, Inc.

Cleveland, Ohio a corporation of Ohio [54] SLEEVE CLUTCH 15 Claims, 7Drawing Figs.

[52] US. Cl 192/74, 192/80, 192/88 [51] Int. Cl ..Fl6d 11/06, Fl6d 13/12[50] Field olSearch 192/74,80, 8803), 79; l88/152(.86)

[56] References Cited FOREIGN PATENTS 222,029 9/1924 Great Britain192/88(B) 630,719 6/1936 Germany 192/88(B) Primary ExaminerAllan D.Herrmann Attorney-Woodhams, Blanchard and Flynn ABSTRACT: A torquetransferring device having a first,

member of circular cross section with axially spaced annular sealingmeans projecting radially therefrom and a passageway communicating froma point exteriorly of the first member to a zone between the pair ofsealing means. A radially flexible friction member is received betweenthe sealing means and positively arranged for rotation with said firstmember, the axial edges of said friction member being sealingly engagedwith said sealing means to define with sealing means a fluidrestrictivechamber around said zone. A second member of circular cross section isconcentrically located with respect to SLEEVE CLUTCH FIELD OF THEINVENTION 7 BACKGROUND OF THEINYENTION The design of torque transferringdevices, both brakes and clutches, for high-speed use, such as use withan automotive turbine, is one which has faced engineers for a longperiod of time and has, insofar as we are aware, never beensatisfactorily solved. While there are large numbers of such devices,for example, clutches, which work to a high level of overalleffectiveness at relatively low speeds, suchas up to 5000 r.p.m., all ofthem insofar as we are aware cannot e be operated at turbine speeds,such as 30,000 r.p.m., without the severe danger of destruction.

' In most instances with which we are acquainted, this problem has beenmet by gearing down the output of the turbine to more conventionalspeeds and applying a torque transferring device, usually a clutch, tothe low-speed side of such gearing. However, this method of dealing withthe problem requires an expensive and heavy group of gears on the outputshaft of the turbine and thus increases the expense of same and tends toaffect adversely the already objectionable tendency of a turbine torespond slowly to changes in fuel supply.

In attempting to meet the aspect of this problem relating to clutches,some interest has been shown in the use of clutches having an annular,radially flexible,-s leeve which may be driven by one of a pair ofconcentric members and be moved radially under a fluid pressure intoengagement with the other such of such pair. While such clutches areknown, and a clutch of this type is suggested in the patent applicationof Sidney Oldburg, Donald J. Fergle and David P. Haas, U.S. Pat. Ser.No. 551,446, filed May 19, 1966, now U.S. Pat. No. 3,412,625, assignedto the same assignee as the present invention, nevertheless, suchclutches as previously known have certain limitations which in turnlimit the effectiveness of the entire unit of which they are a part. Forexample, where the sleeve moves radially outwardly for effecting aclutching operation, it will respond to centrifugal force and in someinstances be thereby urged into engagement with the driven member of theclutch system and impose a drag thereupon. In other instances such as insome types of disc clutches, where the clutch unit is of substantialsize, it requires a substantial mechanical movement to effect clutchengagement and thereby requires the flow of a large amount of fluid toengage the clutching members. As a result, an undesirable time lag mayoccur in the operation of such clutch.

Further, in presently-known clutching devices of this type, andincluding the one illustrated in said U.S. Pat. Ser. No. 551,446,utilizing a radially flexible sleeve, same is tightly clamped at itsaxial ends to the clutch member with which it is associated. As aresult, when fluid pressure is introduced to the system to effect aclutching (or braking) operation, only the central portion of saidsleeve is permitted to elfect the desired radial movement, inward oroutward as the case may be, and as a result only such part of saidsleeve will engage the driven member of the torque transferring device.This requires a larger unit than would be required if the entire sleevecould be brought into engagement with the driven member of the deviceand, further, it tends to concentrate the wear on the radially flexiblesleeve into the central portion thereof.

It is therefore desirable, in furtherance of the objectives set forth insaid U.S. Pat. Ser. No. 551,446 as well as to provide high-speedclutches or brakes for other uses, to provide a clutch or brakestructure capable of operating at turbine speeds, such as 30,000 r.p.m.,but which will correct the problems set forth above as well as otherswhich have been observed with clutches or brakes of the prior art whenapplied to high-speed uses. 7

Accordingly, the objects of this invention include:

1. To provide a torque transferring device capable of operating at highrotative speeds, such as the speeds encountered at the output shaft ofgas turbines used in automotive applications, for example, 30,000 r.p.m.

2. To provide a torque transferring device, as aforesaid, which will besmall and compact while yet capable of a high level of operation.

3. To provide a torque transferring device which is of a small andcompact construction and yet effective in conducting the heat away fromthe engageable components to thereby increase the life of such device.

4. To provide a torque transferring device, as aforesaid, utilizing anannular radially flexible friction member mounted for rotation with theinput member and wherein said flexible friction member is pretensionedto fit onto the input member to compensate to a predetermined extent forthe effect of centrifugal forces developed on said friction member whenthe input member is being driven at a high rotational speed.

5. To provide a torque transferring device, as aforesaid,

wherein the full axial width of the radially flexible friction member ismovable radially and substantially uniformly into engagement with theoutput member so that the engaging surface of the friction member willwear evenly to thereby increase the life thereof and lower. thefrequency at which said sleeve must be replaced.

6. To provide a torque transferring device, as aforesaid, wherein acheck valve is utilized to remove the fluid from the energizing side ofthe radially flexible friction member so that any pressure developed onthe fluid by centrifugal force will be relieved from the energizing sidewhereby the pretensioned fit of the friction member on the input memberwill alone be sufficient to prevent same from dragging on the drum andhigh rotational speeds.

7. To provide a torque transferring device, as aforesaid, wherein theaxial ends of the radially flexible friction member sealingly engagesealing members, which sealing members permit the radially flexiblemember tomove radially over the full axial width thereof.

Other objects and purposes of this invention will be apparent to personsacquainted with torque transferring devices of this general type uponreading the following specification and inspecting the accompanyingdrawings, in which:

FIG. 1 is a longitudinal sectional view of a clutch unit embodying theinvention.

FIG. 2 is a fragmentary section taken on the line 11-11 of FIG. 1.

FIG. 3 is a longitudinal, sectional view of a further clutch unitembodying the invention and designed particularly for connecting a gearof relatively small diameter to a shaft.

FIG. 4 is a sectional vie taken along the line lV-IV of FIG. 3.

FIG. 5 is an enlarged showing of an encircled portion A in FIG. 3.

FIG. 6 is a modification of the radially flexible friction memberconnection in the clutch unit illustrated in FIG. 1.

FIG. 7 is a further modification of the clutch unit illustrated in FIG.I.

Certain terminology-will be used in the following description forconvenience in reference only and will not be limiting. The words up,"down," right and left will designate directions in the drawings to whichreference is made. The words in and out will refer to directions towardand away from, respectively, the geometric center of the device anddesignated parts thereof. Said terminology will include, the words abovespecifically mentioned, derivatives thereof and words of similar import.

The objects and purposes of the invention are met by providing a torquetransferring device having concentric and axially overlapping input andoutput members. A radially flex- }jible friction member is concentricwith both input and output Qmembers and is arranged for rotation withone of said mem- 'bers. Said friction member is preferably pretensionedtoward -the inner of said members so that the pretensioning will opposethe effect of centrifugal force exerted thereon when said 31 frictionmember is driven at a high rotational speed to thereby minimize theotherwise adverse effects of such centrifugal vZforce. Axially facingand spaced edge portions on said one member sealingly engagecorresponding axially facing sur- "ffaces on the flexible frictionmember to define a fluid-restricl t'ive chamber between the frictionmember and said one inember the full axial length of that surface of thefriction ij inember which is opposite said chamber being opposed by a-'cooperating surface of the other of said input and said output,jrnembers. Thus, upon application of a pressurized fluid to thefluid-restrictive chamber, said sealing means will restrict the .llflowof fluid past the axial facing edges of said friction member land saidfluid will cause a radial movement of the friction "inember away fromsaid one member and into engagement with the other member to therebycause the-input and output .rnembers to become frictionally connected toone another.

DETAILED DESCRIPTION -.which one is indicated'at 7. Suitable sealingmeans such as .rings 8 and 9 may be placed between the plates and thehub for preventing leakage of pressure fluid therebetween from :thehereinafter-mentioned pressure chamber. An axial passageway 11 isprovided through said shaft 1 which con- -nects to a radial passageway12. The axial passageway 11 may 'be supplied supplied with pressurefluid, such as oil, in any gconvenient manner (not shown) and the radialpassageway 12 'Jrlelivers said oil to the periphery of the hub'3. I

/ EA radially expansible friction sleeve or'imember 13 is of .uniformradial thickness in an axial direction throughout its full longitudinalextent and is of uniform radial thickness in a circumferential directionexcepting for the irregularities resulting from thehereinafter-mentioned splines or corrugati'ons provided for drivingpurposes. Said sleeve 13 encircles :the hub 3 and in this embodimentwhere, as set forth hereinafter, the sleeve 13 is to expand radiallyoutwardly, said friction member is arranged close to but not necessarilyin bontact with the peripheral surface of the hub 13. Preferably,however, in order to minimize the effects of centrifugal force, saidfriction member 13 will be pretensioned to engage the i'p'e'n'pheralsurface of said hub 3 with a substantial force when the apparatus is inan at-rest condition. The amount of pretensi'oning is so chosen withrespect to the expected operating conditions for the equipment and thediameter of the friction member 13 that said pretensioning force will besubstantially balanced under normal operating conditions by thecentrifugal force effective on said friction sleeve 13 in order thatsaid friction sleeve will continue to contact said peripheral surfacebut only lightly. Thus, a positive force, but preferably only a verysmall positive force, will be required to disengage said friction sleeve13 from the periphery of the hub 3.

' The friction sleeve 13 may be made of any material having a highcoefficient of friction, a good heat resistance and a sufficientelasticity to stretch as required. One effective material for thispurpose is a phenolic-asbestos material having a modulus of elasticityof about 5 X 106 or 6 X 10 sold under the trademark .PYROTEX" byRaybestos-Manhattan, Inc. of Bridgeport, Conn. Suitable means, such asthe splines or corrugations indicated generally at 15 in FIG. 2, areprovided for effecting a positive driving relationship between the hub 3and the friction member 13 in all radial positions of the sleeve 13 butwithout interferring with the radial movement hereinafter describedbetween said friction member 13 and said hub. Said corrugations 15 are,however, made as small as possible without losing said driving functionin order that the sleeve will have as nearly as possible a uniformradial thickness in the circumferential direction.

The member which is to be frictionally related to the shaft 1, in thisinstance a load carrying device such as a gear ring 2, is arranged toencircle the friction member 13 and is mounted in any manner to preventrelative axial movement therebetween. in this instance, the plates 4 and6 are received into suitable recesses 14 and 16 with such clearancesthat the gear 2 is accurately supported concentrically with the shaft 1but appreciable axial movement 'with respect thereto is positivelyprevented. Said gear 2 is then provided with teeth of which one isindicated at 17 as desired. The inner surface 18 of said gear 2 isplaced as close as possible to the friction member 13 when same is inits normal operating position but preferably not in actual contacttherewith (unless for some reason such as in certain transmission usessome drag between the shaft 1 and the gear 2 is desired even when theclutch is disengaged and in such case the pretensioning can bediminished or omitted as desired).

In this embodiment the inner portion 19 of said gear is made of a goodheat-receiving material, such as phosphor-bronze or chromium-copper,whereas the outer portion 21 of said gear is made from any materialappropriate for gear tooth construction, such as steel. The inner andouter portions 19 and 21 may be fixed together in any convenient mannersuch as by being provided with axially arranged interfitting splines orby welding or brazing. An annular lubricant channel 22 is provided inthe exposed faceof the end ring 4 and a plurality of passageways ofwhich one is illustrated at 23 are arranged uniformly andcircumferentially around said end ring 4 for connecting the channel 22to the inner surface of said end ring 4. Preferably said passageways 23will angle radially outwardly as shown to utilize centrifugal force forconducting lubricant from the channel 22 to the inner surface of the endring 4, the passageway 23 meeting the inner face of the end ring 4 at apoint radially outwardly of the surface 18.

A similar lubricant channel 26 is provided on the exposed face of theend ring 6 and corresponding passageways of which one is indicated at 29are provided between the channel 26 and the inner surface of the endring 6, thepassageway 29 meeting the inner face of the end ring 6 at apoint radially outwardly of the surface 18.

Suitable sealing means, such as the .O-rings indicated at 27 and 28, areprovided for sealing the axial ends of the friction member 13 withrespect to the adjacent inner surfaces of the end rings 4 and 6.

The load carrying device 2, whether gear, pulley or other means, isdesirably, though not necessarily, arranged so that its axial center isin radial alignment with the axial center of the friction member 13.Thus, the center of load applied by said friction member is radiallyaligned with the center of said load transmitting device 2 by which goodbalance and stability of the parts are obtained. However, it willberecognized that the concentric arrangement of the parts will provide asufficient stability that if other design reasons require that the powertransmitting device 2 be axially offset from the friction member 13, asillustrated in the embodiments of FIGS. 3-7, the design can be modifiedaccordingly without departing from the broader concepts of the inventionand without losing the stability and reliability required in a device ofthis type.

OPERATION Continuing to consider the above-described device as intendedfor clutching the gear ring 2 to the shaft 1, and continuing to assumethat no drag is desired between said gear ring and the shaft when sameare in an unclutched relationship to each other, the parts will be sodimensioned that in the unclutched position,'the gear 2 will ride on theend rings 4 and 6 concentrically with the shaft 1 but out of contactwith the friction member 13. Further, said friction member 13 willpreferably be sulficiently pretensioned that even at its operatingspeed, it will remain in firm, though preferably light, contact with theperiphery of the hub 3. Pressure fluid, referred to hereinafter as oil,will be supplied by any convenient means illustrated schematically bynozzles 31 and '32 to the oil channels 22 and 26, respectively, fromwhich-said-oil will flow in response to centrifugal force developedthereon by the rotation of the shaft 1 through the connectingpassageways illustrated by the passageways 23 and 29 into the spacebetween the end rings 4 and 6and the opposed surfaces defining therecesses 14 and 16. This will maintain adequate lubrication between saidendrings and said opposed'surfaces of the gear and thereby permitrelative rotation between the shaft and the gear while said parts are inan unclutehed condition. It would be apparent that although no bearingsare expressly shown between the gear ring 2 and the end plates 4' and 6,such may be supplied in any conventional manner if desired.

Further alternatively as above indicated,if for any reason it is desiredthat some drag exist between the gear ring 2 and the shaft 1 when theparts are in their unclutched condition, the amount of pretensioningprovided for thefriction member 13 will be chosen so that at thenormal-operating speed of the shaft 1 the centrifugal force applicabletothe friction member 13 will be such as to expand same outwardly .intothe desired engagement with the surface 18.

,When it is desired to engage the shaft 1' with the gear 2, suitablepressure is introduced irito thepassageway 11 which then travels throughthe passageway 12 and enters the zone between the friction member 13 andthe oppesed peripheral surface of the hub 3. Even though said frictionmember 13 is I initially in direct contact with the peripheral surfaceof the hub 3, oil exiting from the passageway 12 will quickly penetrate.between the friction member and the hub throughout the fullcircumference thereof whereby to apply a radially directed outward forcestretching the friction member and causing same to frictionally engagethe surface 18. If desired, a plurality of passageways corresponding topassageway 12 may be provided in the hub 3 for accelerating thepenetration of pressure fluid between the friction member 13 and saidhub and for insuring that said pressure fluid is introduced uniformlytherebetween. The seals 8 and 9 prevent any appreciable amount of saidpressure fluid from penetrating radially inwardly between the end plates4;and 6 and the hub 3 and the sealing means 27 and 28 insure that noappreciable amount of said pressure fluid will escape outwardly betweenthe friction member 13 and the end plates 4 and 6.

Thus it will be observed the the entire axial length of friction member13 will be urged radially outwardly against the surface 18 for effectinga suitable friction connection between the gear 2 and the shaft 1 Itsradial thickness being axially and circumferentially uniform (actuallyonly substantially uniform circumferentially due to the drivingcorrugations 15) throughout its full length insures that it bearssubstantially simultaneously and uniformly throughout its length andcircumference against the surface 18. The extent of the radial outwardmovement of the friction member 13'is of course in- 21. I Release of thefluid pressure introduced into the passageway 11 will permit the normalresiliency of the friction member 13 to return it to its contractedposition and said clutch is immediately disengaged.

heating of either the friction member 13 or the gear structure lt willbe apparent that under certain conditions the part indicated herein asthe gear 2 may be a shaft or other part into which pressure fluid may beintroduced. In such case, it will be evident that the parts may bereversed but in such case no pretensioning will be necessary or usefuland pressure fluid is introduced at the radial outward side thereof forcontractingly engaging the outer peripheral surface of the hub 3.

It will be further recognized that in view of the foregoing that eitherof the parts 1 and 2 may be nonrotatively mounted or mounted forrotation at a different rate of speed than that of the other partwhereby the friction member 13 and parts associated therewith willfunction as abrake. However, the structure and operation of said partswill be essentially the same as above described in connection with theoperation as a clutch and accordingly, no specific further detailing isneeded.

MODIFICATION OF FIGURES 3-5 The foregoing was of course directed towardstructure wherein the encircling portion was large enough to enable theentire clutch structure to be placedtherewithin. ln'other instanceswhere, continuing to use a gear to illustrate the invention, the gear isofdiameter too small for the clutch struc ture to be placed therewithin,the structure shown in FIGS. 3- -5 will be utilized. Thus, turning nowto FIG. 3, the clutch units illustrated therein comprises an inputmember 111 and an output member 112. The input member 111 and the outputmember 112 are mounted for relative rotation with respect to the frame113 and to each other. 1

The input member 111 has a hub 126 of enlarged diameter,

said hub having a plurality of splines 127 on the outer peripherythereof. A pressure creating device 123 of any convenient sort isconnected through a central axial passageway 122 and a radial passageway128 to the outer periphery of the hub 126.

A pair of axially spaced ring members 131 and 132 are a I secured to theaxial facing sides of thehub 126 by a plurality of bolts 133. A seal,here an O-ring, 134 is provided between the ring 131 and the hub 126. Aseal 136, here also an O-ring, is provided between the ring 132 and theright side of the hub 126. The purpose of this sealing arrangement willbe explained in more detail hereinbelow. The ring members 131 and 132extend radially beyond the peripheral surface of the hub 126 and eachring member 131 and 132 has sealing-ring grooves v(of which one appearsat 138 in FIG. 5) adjacent the outer A ball element 147 is providedbetween the right end of the plug 144 and the left end of the passageway142 so that the opening between the passageway 142 and the orifice 146is regulatable by the ball element 147. That is, when the ball element147 is moved radially outwardly, the passageway 142 is in communicationwith the orifice 146 in the plug 144.

A radially flexible friction member or sleeve 148 having splines 149 onthe radially inner surface thereof which fit between the splines 127 onthe input member 111 is sleevably mounted on the hub 126 and rotatabletherewith. Said splines 149 are of sufiicient radial extent that theyengage each other in both the contracted and expanded condition of thefriction member 148. The friction member 148 is preloaded orpretensioned onto the hub 126 by providing that the diameter of thefriction member 148 is slightly less than the outer diameter of the hub126. The friction member 148 is then press-fitted onto the drive splines127 on the hub 126. The axially facing edges of the friction member 148engage the O-rings 139 and 141 on the ring members 131 and 132,respectively. Thus, when the sleeve 148 expands radially due tocentrifugal force, there appears a zone 151 defined by the hub 126, thefriction member 148, the seals 134,136 and the seals 139, 141.

' In this particular embodiment, the input member 111 is sup- I portedfor rotation relative to the frame 113 by a bearing 152. The bearing 152is spaced axially leftwardly of the radially outwardly extending hub 126by a spacer sleeve 153. Leftward axial displacement of the bearing 152is prevented by a washer 154 which, overlaps the left axial facingsurface of the outer race of the bearing 152, said washer being securedto the .frame 113 by a screw 156.

'. The output member 112 is supported for rotation relative to I theframe 113 by bearings 157 and 158. In this particular em- ,fb'odiment,the output member 112 is concentric with and encircles the input member111. A bearing 159 is located :between the input and output members 111and 112 for Irotatably supporting the members relative to one another.An annular drum member 161 is secured to the output member 112 by aplurality of screws 162. The drum member 161 encir- .c les the radiallyflexible friction member 148 and in this embodiment at least portions ofthe ring members 31 and 32 positioned adjacent the end ends thereof. Agap 163 (FIG. 3) exists between the radially inner surface 160 of thedrum -member 161 and the radially outer surfaces of the ring members 131and 132. A clearance 165 exists between the friction member 148 and thedrum 161. A plurality of radially aligned openings 164 (FIG. 3) areprovided in the drum 161.

Any conventional means indicated schematically merely by the opening 170are provided for introducing lubricant under {at least a light pressureto the bearing 159. The leftward end of said bearing 159 is positionedclose to the adjacent surface of {the ring member 132 so as to provide asufficiently narrow passageway 171 therebetween that the centrifugalforce Eid'eveloped on lubricant therein by the rotation of the ring:member-l32 with respect to the output member 112 will efffe'ct a flowof lubricant radially outwardly and same will -.escape through theopenings 164. Thus, lubricant is drawn .into the bearing 159 and it isdrawn thereinto at a rate at least somewhat proportional to the rate ofrotation of the input and output members with respect to each other andsaid bearing .159 is thereby maintained in a good lubricated condition.

The slingers 135 and 140 are caused to project from the respectivelyopposite and radially outward comers of the end {rings 131 and 132 asshown in FIG. 3. The slinger 140 assists the movement of lubricantthrough the space 171 as above described, In addition, both slingerstend to draw lubricant from the gaps 163 and thereby tend to draw anylubricant escaping past the respective ends of the friction member 148t'o prevent same from entering into the zone 165 between said frictionmember and the surface 160.

- ':':'An output gear 166, or other load carrying device, may be securedto the output member 112 by a key 167 in a well known manner. The outputgear 166 is engageable with other gearing as desired, such as indicatedat 168 As with the friction member 13 referred to in connection withFIGS. 1 and 2, the friction member 148 is of uniform thicknessthroughout its axial and circumferential extent to insure bothsimultaneous and uniform engagement thereof against the surface 160 ofthe drum member 161. The preten- 'sioning above mentioned may be of suchan extent as desired to either entirely prevent contact between thefriction in'ember 148 and the surface 160 when the parts are rotating atnormal operating speed or, if preferred, such pretensioning Ean bechosen so as to provide a light drag between said friction mernber 148and the surface 160. The friction member "148 is made of any materialhaving a high coefficient of friction, of good heat resistivity andhaving sufficient stretch to carry out the radial movement necessary tomove into frictional engagement with the surface 160. The material may,for example, be the same as that above described in connection withFIGS. 1 and 2.

'The clutch drum 161 is made from any material having a high strength,and resistance to fractional wear together with high heat conductivityand specificheat. For example said drum may advantageously be made of achromium-copper which has a thermal conductivity of 0.0042 b.t.u./in. 2)(sec.) (deg. F.). Unalloyed copper offers low temperatures and stressesbut does not offer the surface durability that is available with themuch higher strength chromium-copper As to the heat absorbing andconducting function of the drum, it must be thick enough, regardless ofstrength requirements, to function effectively as a heat sink and tomaintain under normal operating conditions the surface of the drum whichengages the member 148 at an acceptable temperature. Since it is withinnormal engineering competence in the light of the foregoing to selectthe drum thickness necessary to absorb and dissipate the heatanticipated in a particular case, further detailing thereof isunnecessary.

The operation of the device of FIG. 3 will be described in detailhereinbelow for a better understanding of the invention.

The friction member 148 in this embodiment may be considered forpurposes of illustration to be rotatively driven in all conditions ofoperation from the input member 111 through the splines 127 and 149.Application of a fluid pressure to the passageways 122 and 128 by thepressurecreating device 123 will cause a fluid pressure to build up inthe fluid-restrictive chamber 151. This in turn will cause the frictionmember 148 to be urged radially outwardly into engagement with theinternal surface of the clutch drum 161. Engagement of the frictionmember 148 with the clutch drum 161 will couple the input member 111 tothe output member 112. Thus, the speed of rotation of the output member112 will be altered to a speed equal to that of the input member.

The friction member 148 being substantially'unrestricted at its edgeswill expand radially outwardly uniformly along the axial width thereof.This particular characteristic is permitted through the use ofappropriate seals, here O rings, 139 and 141 in the ring members 131 and132,respectively, which slidingly engage the axial facing edged edges ofthe friction member 148. Thus, as the friction member 148 is movedradially, the axially facing edge surfaces of the friction member 148will slide on the seals 139 and 141 without losing the seal createdtherebetween. It is recognized, however, that some fluid will escapebetween the axially facing edges of the friction member 148 and theseals 139 and 141 but this amount of fluid is minimal. That fluid whichdoes escape is due primarily to the effect of centrifugal force thereonand is drawn through the gap 163 (FIG. 3) as above described. Similarly,the 0- rings 134 and 136 substantially prevent the flow of fluidradially inwardly from the fluid-restrictive chamber 151 between the hub126 and the ring members 131 and 132.

The ball element 147 is also affected by centrifugal force and at highrotative speeds is thrown radially outwardly. This permits a fluidconnection between the passageway 142 and the orifice 146 so that anypressure developed within the passageway 128 due to centrifugal forcewill bleed out through the orifice 146 and eliminate the drag betweenthe friction member 148 and the surface which might be otherwise causedby the action of centrifugal force on pres sure fluid within thepassageway 128. The diameter of the orifree 146 is large enough toeffect sufficient oil flow therethrough to cause the ball 147 to sealbut not so large as to prevent the unsealing of the ball by centrifugalforce on release of pressure fluid within the passageway 142.

MODIFICATION OF FIGURES 6 and 7 226 of the inner member 211. The splines249 on the friction member 248 are received in the grooves 272 273between the splines 274 on the sleeve member 272. Thus,- upon theintroduction of a pressurized fluid through a suitable passageway 228into the fluid-restrictive chamber 251 between the friction member 248and the sleeve 272, such fluid will cause the friction member 248 tocontract into engagem ent with the peripheral surface of thehub 226 ofthe input member 21 1.

In this embodiment the hub structure 226' will serve as a heat sink ingenerally the same manner'as above described in connection with the heatsink function of the drum 161. Here the ring members 231 and 232 arefixed with respect to the drum 272 and the radially flexible frictionmember 248 is similarly fixed with respect to the drum 272'. Sealingmeans of which one is shown at 241, here also O-rings; are providedadjacent the opposite axial ends of the friction member 248 forrestricting the escape of pressure fluid from the chamber 251 whilepermitting re radial movement ofv the friction member 248. Seals such asO-rings should also in this embodiment be provided at 236 to preventescape of pressure fluid from the chamber 251.

While in some instances above the inner member 211 has been referred toas an input member and the outer member 212 has been referred to as anoutput member, it will be'understood that this terminology is only forconvenience and that the power flow may go through the system in eitherdirection in any of the embodiments illustrated in FIGS. 1-7 or in anyreasonable modification of any'tliereof. Further, all of the foregoingapparatus has been described in terms of a clutch between a pair ofrotative partsult will be recognized that the invention may also be usedin a brake. In such use the structure will be s essentially the same'butthe operation will be altered in a manner which will be obvious in lightof the foregoing such as making the gear 2 (FIG: 1) fixed as set forthhereinabove and which therefore needs no-detailing.

We claim: r

1. In a force transmitting device for first and second members mountedfor movement with respect to each other, said second member beingconcentric with said first member, the combination comprising:

a radially flexible, annular, friction member sleevably mounted'witltrespect to said first member between said first member and said secondmember and 'driveable from one of said first and second members;

spaced edge portions on one of said first member and said second memberadapted to sealingly engage the substantially axially facing surfaces ofsaid friction member thereby defining a fluid-restrictive cha mberbetween said friction member and said one of said first member and saidsecond member;

fluid pressure means and means providing fluid communication from saidfluid pressure means to said fluid-restrictive chamber;

whereby an application of fluid pressure to said fluid communicationmeans will cause a substantially uniform radial movement of all of saidfriction member and an engagement thereof with the other of said firstmember and said second member to thereby cause said first and secondmembers to become drivingly connected with one another, said sealingengagement of said spaced edge portions and said substantially axiallyfacing surfaces on said friction member restricting the flowof fluidpast said axial facing surfaces of said friction member.

2. The force transmitting device defined in claim 1, wherein saidradially flexible friction member is pretensioned on said first memberwhereby when said clutch is disengaged, the centrifugal effect thereonwill be opposed and the otherwise occurring engagement of said frictionmember with said other of said first and second members will bediminished.

3. The apparatus defined in claim 1, wherein said force transmittingdevice is a clutch.

4. The apparatus defined in claim 1, wherein said force transmittingdevice is a brake.

5. A torque transmitting device defined in claim, claim 1,

wherein said second member is a power transmitting device such as apulley or a gear. I

6. The device defined in claim 1, wherein said second member is a powertransmitting device and the axial center thereof is substantiallyaligned radially with the center of said friction member.

7. A torque transmitting device for first and second rotatable members,said first rotatable member having a pair of axially spaced annularsealing means projecting radially outa second rotatable memberconcentric with said first rotataw ble member and mounted for rotationwith respect thereto, said second rotatable member encircling saidfriction member in close proximity thereto, whereby the inner surface ofsaid second rotatable member is capable of being tightly engaged by saidfriction member; and

means supplying fluid pressure to said passageway whereby an applicationof pressure to the fluid in said passageway will cause all of saidfriction member to expand radially outwardly substantially unituniformly into engagement with said second rotatable member, saidsealing means preventing the flow of fluid past said axially facingsurfaces of said friction member.

8. The torque transmitting device defined in claim 5, wherein said firstrotatable member has a plurality of axial serrations on the outerperiphery thereof between said annular sealing means; and wherein saidradially flexible friction member has axial serrations on the innersurface thereof which are drivingly connected with said serrations onsaid first rotatable member to prevent a relative rotation therebetween.

9. The torque transmitting device defined in claim 7, wherein saidannular sealing means comprises a pair of ring members which projectradially outwardly of said first rotatable member and have sealingmembers connected thereto on the opposed axially facing surfacesthereof;

wherein said axially facing surfaces of said. friction member sealinglyand slidingly engage said sealing members to define a fluid-restrictivechamber between said friction member and said first rotatable member;and

whereby an application of fluid pressure to a said passageway will causea radial movement of all of said friction member into engagement'withsaid second rotatable member to thereby cause said first and secondrotatable members to become drivingly connected with one another, saidsealing members restricting the flow of fluid past the edges of saidfriction member.

10. The torque transmitting device defined in claim 7,

wherein said radially flexible friction member is made of aphenolic-abestos material.

Ill. The torque transmitting device defined in claim 7,

wherein said second rotatable member includes a friction drum whichoverlaps said radially flexible friction member;

material having a thennal conductivity of 0.0042 b.t.u./ (in?) (sec.)(deg. F.). I

13. A torque transmitting device as defined in claim 7 in cluding firstspaced bearing means supporting said second rotatable member and loadtransmitting means supporting said second rotatable member and loadtransmitting means arranged on or for rotation with said secondrotatable member and located between said spaced bearing means; andfurther including second spaced bearing means for rotatively supportthenearest one of said edge portions and wherein introduction means isprovided through said first shaft for introducing lubricant into saidone of said second set of bearings, whereby the said nearest of saidedge portions forms with the adjacent end of said first of said secondpair of bearings a relatively nar- ;row channel which expels lubricantradially outwardly and thereby tends to draw lubricant from saidintroduction means into said one of said second pair of bearing.bearings.

15. The device defined in claim 13, including a flange projecting fromsaid edge portions at their radially outwardly and respectively remotecorners, said flanges projecting away from each other and radiallyoutwardly of the outer periphery of said edge portions whereby lubricantescaping past said friction member from said fluid restrictive chamberwill be drawn between said edge portions and the adjacent surfaces ofsaid second shaft for maintaining lubrication therebetween and forpreventing appreciable travel of said lubricant into the zone betweensaid friction member and the adjacent surface of said second shaft.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 547244 Dated December 5 1 91;

Inventor(s) DO a t It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 3, line 73; 5 x 106 or should read -5 x 10 or Column 10, line 74;transmitting means supporting said second rotatable member and loadtrans mitting means arranged should read transmitting means arranged---.

Column 11, line 6 member axially beyond said second rota table menmember should read --member and the other of said second spaced bearingmeans being positioned on said first rotatable member axially beyondsaid second rotatable member.

Signed and sealed this 8th day of June 1971.

(SEAL) Attest:

EDWARD M.FIETCHER,J'R. WILLIAM E. SCHUYLER, Attesting OfficerCommissioner of Paten

